Focus control apparatus, image pickup apparatus, and focus control method

Abstract

An apparatus configured to perform focus tracking on an object within a detection area to detect a defocus amount within an imaging angle of view includes a memory storing instructions, and a processor configured to execute the instructions to perform focus tracking determination to determine whether or not the focus tracking is to be performed using information about the defocus amount, and acquire information about a shield against the object from image data generated by imaging. The processor is configured to perform the focus tracking determination using information about the shield acquired in the detection area.

What is claimed is: 
     
         1 . An apparatus configured to perform focus tracking on an object, the apparatus comprising:
 at least one memory storing instructions; and   at least one processor configured to execute the instructions to:   perform focus tracking using information about a defocus amount,   wherein a tracking target is changed from a first object to a second object which is in a same category as the first object and has a difference of defocus amount from the first object, and a tracking target is not changed from the first object to a third object which is a different category of the first object and has the difference of defocus amount from the first object,   wherein, in a case where a first object has been tracked as a focus tracking target and the first object is hidden by a second object which is in a same category as the first object, the focus tracking target is changed to the second object, and   wherein, in a case where the first object has been tracked as the focus tracking target and the first object is hidden by a third object which is in a different category as the first object, the focus tracking target is not changed to the third object for a predetermined time.   
     
     
         2 . The apparatus according to  claim 1 , wherein the processor is configured to acquire information about a shield against the first object, and perform focus tracking determination using the information about the shield against the first object. 
     
     
         3 . The apparatus according to  claim 2 , wherein the information about the shield against the first object includes a category about the second object or the third object. 
     
     
         4 . The apparatus according to  claim 1 , wherein in a case where the first object is hidden by the second object that has the difference of defocus amount from the first object, the focus tracking target is changed to the second object. 
     
     
         5 . The apparatus according to  claim 1 , wherein in a case where the first object is hidden by the third object that has the difference of defocus amount from the first object, the focus tracking target is not changed to the third object for a predetermined time. 
     
     
         6 . The apparatus according to  claim 2 , wherein the processor is configured to determine that:
 the focus tracking is to be performed in a case where the information about the shield is not acquired in a detection area to detect a defocus amount within an imaging angle of view, and   the focus tracking is not to be performed in a case where the information about the shield is acquired in a detection area to detect a defocus amount within an imaging angle of view.   
     
     
         7 . The apparatus according to  claim 2 , wherein the processor is configured to determine that:
 the focus tracking on a specific object is to be performed in a case where the information about the shield acquired in a detection area to detect a defocus amount within an imaging angle of view indicates that the shield is the specific object, and   the focus tracking on the specific object is not to be performed in a case where the information about the shield acquired in a detection area to detect a defocus amount within an imaging angle of view indicates that the shield is not the specific object.   
     
     
         8 . The apparatus according to  claim 7 , wherein the processor is configured to determine that the focus tracking on the specific object is to be performed in a case where the information about the shield acquired in the detection area indicates that the shield is the specific object and switching of the object for the focus tracking is permitted. 
     
     
         9 . The apparatus according to  claim 2 , wherein the processor is configured to acquire the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a side closer than the object. 
     
     
         10 . The apparatus according to  claim 2 , wherein the processor is configured to perform:
 the focus tracking in a case where the information about the defocus amount is within a predetermined range, and   the focus tracking determination without using the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a far side beyond the predetermined range.   
     
     
         11 . The apparatus according to  claim 2 , wherein the processor is configured to:
 acquire the information about the shield for each frame of the image data,   store the information about the defocus amount in a frame where the information about the shield was acquired, and   acquire the information about the shield using stored information about the defocus amount in a frame where the information about the shield was not acquired.   
     
     
         12 . The apparatus according to  claim 11 , wherein the processor is configured to acquire the information about the shield based on information about a defocus amount at which a difference from the information about the stored defocus amount or a difference from information about a defocus amount predicted using the information about the stored defocus amount is equal to or smaller than a predetermined value in the frame in which the information about the shield was not acquired. 
     
     
         13 . The apparatus according to  claim 2 , wherein the processor is configured to acquire information about the shield using a convolutional neural network. 
     
     
         14 . The apparatus according to  claim 1 , wherein the processor is configured to:
 determine whether the object within a detection area to detect a defocus amount within an imaging angle of view is a moving object or a non-moving object and perform focus control,   perform the focus control based on a defocus amount detected for the non-moving object in a case where it is determined that the focus tracking is to be performed and it is determined that the object within the detection area is the non-moving object, and perform the focus control based on a defocus amount predicted using a defocus amount detected for the moving object in a case where it is determined that the focus tracking is to be performed and it is determined that the moving object is the moving object, and   not perform the focus control in a case where it is determined that the focus tracking is not to be performed and it is determined that the object in the detection area is the non-moving object, and perform the focus control using a predicted defocus amount without using the defocus amount in a case where it is determined that the focus tracking is not to be performed and it is determined that the object in the detection area is the moving object.   
     
     
         15 . An optical apparatus comprising the apparatus according to  claim 1 . 
     
     
         16 . An image pickup apparatus comprising:
 the apparatus according to  claim 1 ; and   an image sensor configured to image the object within an imaging angle of view.   
     
     
         17 . A method configured to perform focus tracking on an object, the method comprising:
 performing focus tracking using information about a defocus amount,   wherein a tracking target is changed from a first object to a second object which is in a same category as the first object and has a difference of defocus amount from the first object, and a tracking target is not changed from the first object to a third object which is a different category of the first object and has the difference of defocus amount from the first object,   wherein, in a case where a first object has been tracked as a focus tracking target and the first object is hidden by a second object which is in a same category as the first object, the focus tracking target is changed to the second object, and   wherein, in a case where the first object has been tracked as the focus tracking target and the first object is hidden by a third object which is in a different category as the first object, the focus tracking target is not changed to the third object for a predetermined time.   
     
     
         18 . The method according to  claim 17 , further comprising acquiring information about a shield against a first object and performing focus tracking determination using the information about the shield against the first object. 
     
     
         19 . The method according to  claim 18 , further comprising acquiring the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a side closer than the object. 
     
     
         20 . The method according to  claim 18 , further comprising:
 performing focus tracking in a case where the information about the defocus amount is within a predetermined range; and   performing focus tracking determination without using the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a far side beyond the predetermined range.   
     
     
         21 . The method according to  claim 18 , further comprising:
 acquiring the information about the shield for each frame of the image data;   storing the information about the defocus amount in a frame where the information about the shield was acquired; and   acquiring the information about the shield using stored information about the defocus amount in a frame where the information about the shield was not acquired.   
     
     
         22 . A non-transitory computer-readable storage medium storing a program that causes a computer to execute a method configured to perform focus tracking on an object, the method comprising:
 performing focus tracking using information about a defocus amount; and   wherein a tracking target is changed from a first object to a second object which is in a same category as the first object and has a difference of defocus amount from the first object, and a tracking target is not changed from the first object to a third object which is a different category of the first object and has the difference of defocus amount from the first object,   wherein, in a case where a first object has been tracked as a focus tracking target and the first object is hidden by a second object which is in a same category as the first object, the focus tracking target is changed to the second object, and   wherein, in a case where the first object has been tracked as the focus tracking target and the first object is hidden by a third object which is in a different category as the first object, the focus tracking target is not changed to the third object for a predetermined time.   
     
     
         23 . The non-transitory computer-readable storage medium according to  claim 22 , further comprising:
 acquiring information about a shield against the first object, and   performing focus tracking determination using the information about the shield against the first object.   
     
     
         24 . The non-transitory computer-readable storage medium according to  claim 22 , further comprising acquiring the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a side closer than the object. 
     
     
         25 . The non-transitory computer-readable storage medium according to  claim 23 , further comprising:
 performing focus tracking in a case where the information about the defocus amount is within a predetermined range; and   performing focus tracking determination without using the information about the shield in a case where the information about the defocus amount acquired in a detection area to detect a defocus amount within an imaging angle of view indicates a far side beyond the predetermined range.   
     
     
         26 . The non-transitory computer-readable storage medium according to  claim 23 , further comprising:
 acquiring the information about the shield for each frame of the image data;   storing the information about the defocus amount in a frame where the information about the shield was acquired; and   acquiring the information about the shield using stored information about the defocus amount in a frame where the information about the shield was not acquired.